Timepiece calibration recording apparatus



Dec. 5, 1950 w. J. LORlA EI'AL 2,532,631

TIMEPIECE CALIBRATION RECORDING APPARATUS Filed Sept. 15, 945 sSheets-Sheet 1 INVENTORS Jana/n5 Sui/RE ATTORN EY Dec. 5, 1950 W. J.LORIA EI'AL TIMEPIECE CALIBRATION RECORDING APPARATUS Filed Sept. 13,1945 3 Sheets-Sheet 2 m&

me mmm N R l\ W3 m N T lwp A P km x m N? E? mw n" %w\ E Q i Ljd firkDec. 5, 1950 w. J. LORIA ETAL 3 TIMEPIECE CALIBRATION RECORDINGAPPARATUS Filed Sept. 13, 1945 3 Sheets-Sheet 5 ATTORNEY Patented Dec.5, 1950 PATENT OFFICE TIMEPIECE CALIBRATION RECORDING APPARATUS WalterJ. Loria and Jerome Suhre, New York, N. Y.

Application September 13, 1945, Serial No. 615,958

9 Claims. 1

The present invention relates to timepiece calibration recordingapparatus and more particularly to such apparatus of the all-electronictype which is substantially inertialess for recording the accuracy of awatch or clock in order to observe its rate of gain or loss of time.

In the repair or adjustment of a watch or clock and also in routinetests it is essential to speedily determinethe accuracy thereof. It isalso important to know the characteristics of the beat of a watch orclock so that irregular beats may be detected.

Heretofore, it has been usual for the horologist to utilize the old timeworn method of observing its rate over a long period of time as comparedwith a standard chronometer. Other methods have been developed, as forexample, the utilization of the stroboscopic principle as applied tovisual indicators. Recording instruments have been used with electronicstylus control and embodying rotating drums and stylus action based onthe principle of inked ribbon and reciprocating stylus action producingresponse in the form of a series of dots corresponding to the beat ofthe watch.

These instruments are incapable of responding to rapid beat movementsand give no qualitative analysis either of the beat or of the soundsproduced by the movement between the beats. The present inventioncontemplates the provision of a watch and clock time checking devicethat is sensitive to the beat of the most rapid 'watch and accuratelychecks and records the degree of regulation of the timepiece underexamination, as well as the nature and characteristic of the beat, andthe integrated sounds produced by the movement, to a degree notheretofore obtainable and the operation of which simplifies the knownmethods of watch and clock regulation.

The present invention also contemplates a means of recording the beat ofa watch and the integrated sounds of a watch or clock mechanism so thatqualitative analysis thereof may speedily and accurately be made, anaccomplishment Furthermore, the invention provides means for recordingthe duration of the beat of the Watch and the integrated sounds thereof,an achievement which has heretofore been unknown in the horological art.

In accordance with the invention there is provided timepiece calibrationrecording apparatus comprising an electrical pickup effective to deriveperiodic electrical signals precisely related in frequency to the timingof a timepiece being calibrated, a, standard source of periodicreference electrical signals, and a moving carriage adapted to receive acalibration chart movable therewith. The apparatus also includes arecording stylus movable across a chart on said carriage to scan thesame and means responsive jointly to the derived signals and thereference signals for causing the stylus to make two groups of periodictraces on a chart on said carriage, each positioned in dependence uponthe frequency of one of such signals, whereby the relative patterns ofthe traces are representative of the calibration of the timepiece.

For a better understanding of the present invention, together with otherand further objects thereof, reference is had to the followingdescription taken in connection with the accompanying drawings, and itsscope will be pointed out in the appended claims.

The accompanying drawings referred to herein and constituting a parthereof illustrate an embodiment of the invention and together with thedescription serve to explain the principles of the invention.

Figures 1a and lb are schematic wiring diagrams of electric elementsused in the apparatus.

Figure 2 is a top elevation, partly in cross section, of one embodimentof the calibrating apparatus according to the present invention.

Figure 3 is a side elevation, partially in cross section, of theapparatus of Figure 2.

Figure 4 is a diagram of a pattern produced by the apparatus.

Referring now to Figures 2 and 3 of the drawings, the timepiececalibration recording apparatus embodying the invention and adapted tomake a record on an electrosensitive chart comprises a portable casinincluding a chassis portion 59 and a hood portion 9. Secured to the sidewall 8 of hood 9 there is provided a mounting 3 so arranged that atimepiece such as a watch can be placed thereon with any orientation.Afiixed to the mounting 3 is an electrical pickup effective to deriveperiodic electrical signals precisely related in frequency to the timingof the timepiece being calibrated. This apparatus may comprise amicrophone ii of the crystal or contact type cushioned to absorb outsideshocks and effective to develop signals representative of the soundbeats of the timepiece in duration and frequency.

The recording apparatus also includes a moving carriage adapted toreceive a calibration chart; specifically projecting through base 2 ofchassis '60 is a shaft 5 of synchronous motor 6 which is affixed to theunderside of base 2. Secured to the shaft 5 of synchronous motor 6 is anelectrically conductive disc turntable l for receiving a circular chart28 of electrosensitive type effective to produce a mark or trace varyingin intensity and duration with the value of an electric current passedtherethrough. The synchronous motor 6 is of-a conventional type dcsigned to rotate the turntable I at 60 R. P. M. when connected to thecommercial 60 cycle alterhating-current supply. The recording apparatusfurther includes a recording stylus movable across the chart 28 on thecarriage or turntable I to scan the same. Specifically, the stylus H isreciprocable rad ally across the chart 28 to scan the same with atime-linear trace movement and a rapid retrace movement. The mechanismfor imparting this motion to the stylus ll comprises a shaft I 5projecting through the wall 8 of hood 9 and connected at one end withstylus I I, which is a metal ballpointed needle and so aflixed thatoutward movement of shaft IE] will project stylus H radially across andtoward the center of turntable 1. Shaft H! is arranged within housing 9to be guided accurately in its movement toward the center point ofturntable i by guide bars [2 which guide a cross piece i to which shaftII! is affixed. The shaft l and stylus H are actuated by cam l revolvedby a motor IE, affixed to the top of chassis 65. Guide bars l2aresecured to end plates I! and I8 which are aifixed and secured to thebase 2 of chassis 60. Shaft ID has connected or afiixed to its endopposite the stylus a roller 39 which rides on cam I5. The drivingmechanism for moving the carrage or turntable l, specifically thesynchronous motor 6, operates at a speed which is Very high relative tothat of the driving mechanism for the stylus II, that is, thesynchronous motor iii. For example, the motor 6 may drive the turntableat 60 R. P. M. while the motor it drives the cam l5 at 1 R. P. M.

Enclosed within housing 9 and affixed to the base 2 of chassis 6B isamplifier unit I9, a conventional high-gain electronic amplifierdesigned to produce a power output of 5 watts from the beat of the watchunder test. Specifically, the amplifier unit l9 includes a conventionalpentode amplifier tube Gila having its grid-cathode circuit connected tothe microphone pickup d and provided with a grid-leak resistor El and aconventional cathode bias circuit 62. The anode circuit of amplifier 50ais provided with a load resistor 63 coupled by way of a capacitor 64 tothe grid-cathode. circuit of a second pentode amplifier 'tube 52, theanode circuit of which is coupled by way of a load res stor 64 and acoupling condenser 55 to the grid-cathode circuit of a power amplifiertube 55. The tubes 52 and 68a. areprovided with grid-leak resistors 67and 58, respectively, and cathode biasing circuits 69 and 'lflrespectively. The anode circuit of amplifier tube 66 is coupled by wayof a transformer 1| to the conductive stylus H by suitable flexible orsliding contact connection (Figure 1a) to allow for its reciprocation.The recording apparatus includes also a standard source of periodicreference signals having a frequency of a value commensurable with thenormal frequency of the sound beats of the timepiece. This referencesignal source includes, enclosed within housing 9 and affixed to a sidewall thereof, a tuning fork unit 29, consisting of tuning fork 43!, madeof magnetic material, an actuating electromagnet 43 Wound on a soft ironcore 55 mounted at right angles to one of the tines 53 of tuning forkdl. Also at right angles to the opposite tine 5 3 of tuning fork il is apickup winding 32 which contains a permanent magnet core 24. Tuning forkunit All also includes a feedback amplifier comprising a triode vacuumtube 4? having its gridcathode circuit connected to the pickup winding42 and its anode circuit coupled by way of load resistor 72 and couplingcondenser 575 to the gridcathode circuit of a second triode vacuum tube46, the anode circuit of which is connected to excite the actuatingelectromagnet :33 through a load resistor 43a. The tubes .6 and ll areprovided with cathode bias circuits 55 and 55, respectively, while tube46 is provided with a grid-' leak resistor 13.

The recording apparatus of the invention also includes a power supplycircuit which may be conventional in construction, comprising an inputtransformer 23 having a primary winding 23!; connected to supply circuitterminals 14, 14 through either a push button switch 28 or the contacts22a of a relay 22, the winding of which is connected across theterminals 14, M through the normally closed contacts of a limit switch24 actuated b the cross bar M of the stylus reciprocating mechanism. Thetransformer 23 is provided with a low-voltage secondary winding 23b forenergizing the cathode heaters of the several amplifier tubes of thesystem; with a secondar winding 230 for energizing the filament of adouble-anode rectifier tube 26; and witha mid-tapped secondary winding2301 providing with tube 26 a full-wave rectifying circuit. The filamentof tube 26 is connected, through a conventional filter c rcuit 75, tothe terminal +B, which is the positive terminal of the power supplyoutput circuit. One of the chokes of the filter unit 15 comprises thewinding of a relay 25 having contacts 21, 21a connected to complete thecircuits of the motors l5 and 6, respectively.

Tuning fork unit ii] is a precision oscillator circuit whose frequencyis mechanically determined by the fundamental frequency of the tuningfork 6| in a conventional manner. Briefly, vibration of tine 54 at thenatural frequency of fork 4i induces a periodic voltage of the samefrequency in pickup winding 42. This voltage is amplified in tubes 51and 46 and. fed back to actuating winding 13. This regenerative actionmaintains the tuning fork 4! in oscillation at its natural frequency ina conventional manner well understood in the art, and develops acrossload resistor 43a a periodic voltage constituting the source ofreference signals of the apparatus. As stated above, the naturalfrequency of the tuning fork 6| should be commensurable with the normalfrequency of the timepiece to be calibrated, that second, thusdeveloping l2 oscillations per watch beat.

The recording apparatus also includes repeater means for clipping thereference signals to develop a periodic short-duration pulse Wave andmeans responsive jointly to the signals derived from the watch beat andthe reference signals for causing the stylus II to make two groups ofperiodic traces on a chart 28 on the turntable I, each positioned independence upon the frequency of one of such signals. To this end, thevoltage across resistor 43a, is fed to vacuum tube 48 included inamplifier unit l9 through a coupling capacitor 16. Tube 48 is connectedas a conventional resistance coupled amplifier but biased almost tocut-ofi'. The effect of this excessive bias, provided by cathode biasresistor 50 bypassed by capacitor '11, is to cause rectification andclipping of the output of tuning fork unit 40, producing a unilateralpulsating wave com prising short-duration pulses consisting of only thepeaks of the tuning fork oscillations. The output of amplifier tube 48developed across resistor "is fed through coupling capacitor to thescreen grid of vacuum tube 52 in amplifier 19. Thus, both the signalsderived from the watch beats and the reference signals are amplifled intubes 52' and 66 and passed through transformer H to stylus H.Therefore, amplifier 19 comprises means for impressing the signalsderived from the watch beats and the clipped reference signals on thestylus l I simultaneously.

In the use of the calibrating apparatus of the invention to ascertainthe accuracy of the watch or clock under test, the timepiece is placedon mounting 3 in direct contact with microphone 1. Push button 20 ismomentarily depressed, thus energizing the primary winding oftransformer 23 and of relay 22, causing relay 22 to close its contacts22a, thus maintaining flow of current to the primar winding oftransformer 23 after removal of pressure on button 20. The energizingcurrent passing through the relay 23 likewise passes through the contactpoints of limit switch 24. The secondary winding 23d of transformer 23is connected to relay 25 through the rectifier 26 and, upon the heatingof the cathodes of the tubes of the amplifier l9, relay 25 will beenergized by the resulting flow of anode current, thus closing contacts21, 21a of relay 25 and causing motors 6 and [6 to operate. Motors 6 andI6 are synchronous motors which have previously been described asoperating at speeds of 60 R. P. M. and 1 R. P. M., respectively, fromcommercial alternating-current supply sources. The rotation of motor 6in turn rotates turntable 1 through shaft 5. An appropriately sizeddiscshaped chart of electrically sensitive paper 28, previouslydescribed, is placed on turntable I and secured in place and is rotatedby the turntable 'l at a rate of 60 R. P. M. Stylus II is broughtautomatically into contact with the paper placed on the turntable 1 and,as the turntable 1 rotates progressively, moves radially toward thecenter of the disc, at the same time producing on the surface of thepaper black markings corresponding in intensity and duration to the beatof the timepiece under test and to the frequency of the tuning fork 4!.The stylus H is driven by shaft [0, guided, as already stated, by barsl2 and actuated by cam l5 driven by motor Hi. When cam I5 completesone-half of a revolution, stylus ll will have reached its terminal pointon its approach to the center of turntable i and the test run will havebeen completed. The amplified and clipped reference signals from tuningfork unit in impressed on stylus ll produce a series of radial traces 28each comprising a series of dots representative of the short-durationbeats of the tuning fork oscillations. Simultaneously, the amplifiedsignals derived from the watch beats by the microphone 4 produce aseries of approxi mately radial traces 28b comprising a series ofarcuate dashes representative of the watch beats in duration and time.The watch beats themselves are in the form of pulses of damped transientoscillations, the duration of which indicates to a horologist the natureof the escapement action.

The radial traces 28a corresponding to the frequency of the tuning forkare reference lines and if, for example, a 60 cycle fork is used therewill be 60 radial lines equally angularly spaced around the chart 28whose accuracy will be equal to the standard provided by the tuningfork. Against these traces will be read the record of the rate of gainor loss of the watch under test. If, for example, the watch under testproduces a trace which cuts across a space separating two adjacentradial reference traces produced by the fork, there will be a gain orloss depending upon the direction of the curve of the watch trace, whichcan easily be seen.

The rate of gain or loss may be mathematically determined since, in theinstrument described, the turntable 1 rotates at 60 R. P. M. or onerevolution per second while the tuning fork 4! has a frequency of 60cycles per second so that the space between adjacent radial referencetraces is equal to one-sixtieth of a second. A gain of one radial lineor one-sixtieth of a second in the run which is timed for one-halfminute by onehalf revolution of cam 15 shows that the timepiece isgaining one-thirtieth of a second in a minute or two seconds per hour or48 seconds per day. Since there is considerable space between eachreference trace, extremely small variations in time can be readilydetected. It will be observed that cutting of the reference traces bythe watch traces in a counterclockwise direction indicates afast-running movement.

The regularity of the beat of the watch under test can quickly bedetermined by counting the reference traces between the traces producedby the tick of the watch. Equal spacing between traces on a five or sixbeat watch indicates a regular beat. Uneven spacing indicates anirregular beat.

It is also to be observed that this invention provides a means forinstantly determining the number of beats per second produced by thewatch, a feature new and unique. The apparatus is also capable ofcalibrating watches of any beat rate.

Markings appearing between the regular radial watch traces indicatesounds produced by an improperly operating watch which a horologist caninterpret. Further, the trace-developing means are inertialesselectronic circuit elements and apparatus so that sounds of a durationas brief as 10000 of a second may be recorded. A qualitative analysis ofthe beat may be made by an observation of the track of light and darkmarkings within the beat marks which will be of prime importance to thehorologist as indicating the condition of the timepiece under test.

While we have described in detail a modification of the presentinvention illustrated as embodied in a watch rate checking instrument.it is to be understood that changes may occur to those skilled in thisart.

The invention in its broader aspects is not limited to the specificmechanism shown and described but departures maybe made therefrom withinthe scope of the accompanying claims without departing from theprinciples of the invention and Without sacrificing its chiefadvantages. V V

What is claimed is:

l. Timepiece calibration recording apparatus comprising: an electricalpickup effective to derive periodic electrical signals precisely relatedin frequency to the timing of a timepiece being calibrated; a standardsource of periodic reference electrical signals; a moving carriageadapted to receive a calibration chart movable therewith; a recordingstylus movable across a chart on said carriage to scan the same; andmeans responsive jointly to said derived signals and said referencesignals for causing said stylus to make two groups of periodic traces ona chart on said carriage, each positioned in dependence upon thefrequency of one of said signals, whereby the relative patterns of saidtraces are representative of the calibration of said timepiece.

2. Timepiece calibration recording apparatus comprising: an electricalmicrophone effective to derive periodic electrical signalsrepresentative of the sound beats of a timepiece being calibrated induration and frequency; a standard source of periodic referenceelectrical signals; a moving carriage adapted to receive a calibrationchart movable therewith; a recording stylus movable across a chart onsaid carriage to scan the same; and means responsive jointly to saidderived signals and said reference signals for causing said stylus tomake two groups of periodic traces on a chart on said carriage, eachpositioned in dependence upon thefrequency of one of said signals,whereby the relative patterns of said traces are representative of thecalibration of said timepiece.

3. Timepiece calibration recording apparatus comprising: an electricalpickup effective to derive periodic electrical signals precisely relatedin frequency to the timing of a timepiece being calibrated; a standardsource of periodic reference electrical signals having a frequency of avalue commensurable with the normal frequency of the sound beats of saidtimepiece; a moving carriage adapted to receive a calibration chartmovable therewith; a recording stylus movable across a chart on saidcarriage to scan the same; and means responsive jointly to said derivedsignals and said reference signals for causing said stylus to make twogroups of periodic traces on a chart on said carriage, each positionedin dependence upon the frequency of one of said signals, whereby therelative patterns of said traces are representative of the calibrationof said. timepiece.

' 4. Timepiece calibration recording apparatus comprising; an electricalpickup elfective to derive periodic electrical signals precisely relatedin frequency to the timing of a timepiece being calibrated; a standardsource of periodic reference electrical signals; a turntable adapted toreceive a circular calibration chart; a recording stylus movableradially across a chart on said carriage .to scan the same; and meansresponsive jointly to said derived signals and said reference signalsfor causing said stylus to make two groups of radial periodic traces ona chart on said carriage, each positioned in dependence upon thefrequency of one of said signals, where- 8 by the relative patterns ofsaid tracesare representative of the calibration of said timepiece.

5. Timepiece calibration recording apparatus comprising: an electricalpickup effective to derive periodic electrical signals precisely relatedin frequency to the timing of a timepiece being calibrated; a standardsource of periodic reference electrical signals; a moving carriageadapted' to receive a calibration chart; a recording stylus reciprocableacross a chart on said carriage to scan the same with time-linear tracemovement and a rapid retrace movement; and means responsive jointly tosaid derived signals and said reference signals for causing said stylusto make two groups of periodic traces on a chart on said carriage, eachpositioned in dependence upon the frequency of one of said signals,whereby the relative patterns of said traces are representative of thecalibration of said timepiece.

6. Timepiece calibration recording. apparatus adapted to make a recordon an electrosensitive chart comprising: an electrical pickup effectiveto derive periodic electrical signals precisely related in frequency tothe timing of a timepiece being calibrated; a standard source ofperiodic reference electrical signals; a moving carriage adapted toreceive a calibration chart movable therewith; a recording stylusmovable across a chart on said carriage to scan the same; and means forimpressing both said signals on said stylus simultaneously for causingsaid stylus to make two groups of periodic traces on a chart on saidcarriage, each positioned in dependence upon 7 the frequency of one ofsaid signals, whereby the relative patterns of said traces arerepresentative of the calibration of said timepiece.

7. limepiece calibration recording apparatus comprising: an electricalpickup effective to derive periodic electrical signals precisely relatedin frequency to the timing of a timepiece being calibrated; a standardsource of periodic reference electrical signals; a moving carriageadapted to receive a calibration chart movable therewith; a recordingstylus movable across a chart on said carriage to scan the same; drivingmechanism for moving said stylus; driving mechanism for moving saidcarriage at a speed which is high relative to that of said stylus; andmeans responsive jointly to said derived signals and said referencesignals for causing said stylus to maketwo groups of periodic traces ona chart on said carriage, each positioned in dependence upon thefrequency of one of said signals, whereby the relative patterns of saidtraces are representative of the calibration of said timepiece.

8. Timepiece calibration recording apparatus comprising: an electricalpickup effective to derive periodic electrical signals precisely relatedin frequency to the timing of a timepiece being calibrated; a standardsource of periodic reference electrical signals; repeater means forclipping said reference signals to develop a periodic short-durationpulse wave; a moving carriage adapted to receive a calibration chart; arecording stylus movable across a chart on said carriage to scan thesame; and means responsive jointly to said derived signals and saidclipped reference signals for causing said stylus to make two groups ofperiodic traces on a chart on said carriage, each positioned independence upon the frequency of one of said signals, whereby therelative patterns of said traces are repr sentative of the calibrationof said timepiece.

9. Timepiece calibration recording apparatus adapted to make a record onan electrosensitive chart comprising: an electrical pickup efiective toderive periodic electrical signals precisely related in frequency to thetiming of a timepiece being calibrated; a standard source of periodicreference electrical signals; repeater means for clipping said referencesignals to develop a periodic short-duration pulse Wave; a movingcarriage adapted to receive a calibration chart; a recording stylusmovable across a chart on said carriage to scan the same; and means forimpressing said derived signals and said clipped reference signals onsaid stylus simultaneously for causing said stylus to make on said chartone trace comprising a series of dots representative of said referencesignals and a second trace comprising a series of dashes representativeof said derived signals in timing and duration, whereby the relativepatterns of said traces are representative of the calibration of saidtimepiece.

WALTER J. LORIA. JEROME SUI-IRE.

10 REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS

